Extra inspectors at entry points including Heathrow Airport are helping the Food & Environment Research Agency (FERA) intercept more pests and diseases on imported plant material, the organisation says.
FERA increased the level of plant health inspection at Heathrow and Manchester Airports as part of changes to the regime introduced in April.
The agency's senior entomologist Chris Malumphy said: "There are a lot of new inspectors and we are finding a bigger range of things. We are stopping a lot more, including finished plants going to supermarkets, and we are taking statutory action and destroying them."
He added that molecular testing techniques were also allowing pests to be identified at the larval stage, much earlier than previously.
Senior mycologist Paul Beales said researchers were always looking for new methods to speed up the process and get results as quickly as possible. "We have methods now that we can use in the field, which takes the time down to minutes," he added.
"Previously, if symptoms looked like Phytophthora, the crop had to be stopped and tested. Seventy per cent came back negative because the symptoms are also caused by other things.
"With the new methods, inspectors can run a sample through a machine and know in a few minutes if the plant has Phytophthora. This has saved growers a lot of money."
Principal plant health and seeds inspector Derrick McCann added that there were always improvements to be made. "Money and staff are the restricting factors and we have a sliding scale of risk and targets of what we need to find. It is finding the next problem that is the issue. What wasn't a problem before could become one if circumstances change."
FERA has controversial plans for inspection price increases to cover "full cost recovery".
40,000 - The number of customers that FERA has, along with 1,000 collaboration partners spread across 102 countries